| Message ID | 1403909347-31622-5-git-send-email-mihai.caraman@freescale.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 28.06.14 00:49, Mihai Caraman wrote: > On book3e, guest last instruction is read on the exit path using load > external pid (lwepx) dedicated instruction. This load operation may fail > due to TLB eviction and execute-but-not-read entries. > > This patch lay down the path for an alternative solution to read the guest > last instruction, by allowing kvmppc_get_lat_inst() function to fail. > Architecture specific implmentations of kvmppc_load_last_inst() may read > last guest instruction and instruct the emulation layer to re-execute the > guest in case of failure. > > Make kvmppc_get_last_inst() definition common between architectures. > > Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> > --- > v4: > - these changes compile on book3s, please validate the functionality and > do the necessary adaptations! > - common declaration and enum for kvmppc_load_last_inst() > - remove kvmppc_read_inst() in a preceding patch > > v3: > - rework patch description > - add common definition for kvmppc_get_last_inst() > - check return values in book3s code > > v2: > - integrated kvmppc_get_last_inst() in book3s code and checked build > - addressed cosmetic feedback > > arch/powerpc/include/asm/kvm_book3s.h | 26 ------------------ > arch/powerpc/include/asm/kvm_booke.h | 5 ---- > arch/powerpc/include/asm/kvm_ppc.h | 24 +++++++++++++++++ > arch/powerpc/kvm/book3s.c | 11 ++++++++ > arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++++-------- > arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++++++++++++---------- > arch/powerpc/kvm/book3s_pr.c | 45 ++++++++++++++++++++++++-------- > arch/powerpc/kvm/booke.c | 3 +++ > arch/powerpc/kvm/e500_mmu_host.c | 6 +++++ > arch/powerpc/kvm/emulate.c | 18 ++++++++----- > arch/powerpc/kvm/powerpc.c | 11 ++++++-- > 11 files changed, 128 insertions(+), 76 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h > index ceb70aa..1300cd9 100644 > --- a/arch/powerpc/include/asm/kvm_book3s.h > +++ b/arch/powerpc/include/asm/kvm_book3s.h > @@ -276,32 +276,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu) > return (kvmppc_get_msr(vcpu) & MSR_LE) != (MSR_KERNEL & MSR_LE); > } > > -static inline u32 kvmppc_get_last_inst_internal(struct kvm_vcpu *vcpu, ulong pc) > -{ > - /* Load the instruction manually if it failed to do so in the > - * exit path */ > - if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) > - kvmppc_ld(vcpu, &pc, sizeof(u32), &vcpu->arch.last_inst, false); > - > - return kvmppc_need_byteswap(vcpu) ? swab32(vcpu->arch.last_inst) : > - vcpu->arch.last_inst; > -} > - > -static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu) > -{ > - return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu)); > -} > - > -/* > - * Like kvmppc_get_last_inst(), but for fetching a sc instruction. > - * Because the sc instruction sets SRR0 to point to the following > - * instruction, we have to fetch from pc - 4. > - */ > -static inline u32 kvmppc_get_last_sc(struct kvm_vcpu *vcpu) > -{ > - return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu) - 4); > -} > - > static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu) > { > return vcpu->arch.fault_dar; > diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h > index c7aed61..cbb1990 100644 > --- a/arch/powerpc/include/asm/kvm_booke.h > +++ b/arch/powerpc/include/asm/kvm_booke.h > @@ -69,11 +69,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu) > return false; > } > > -static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu) > -{ > - return vcpu->arch.last_inst; > -} > - > static inline void kvmppc_set_ctr(struct kvm_vcpu *vcpu, ulong val) > { > vcpu->arch.ctr = val; > diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h > index e2fd5a1..ec326c8 100644 > --- a/arch/powerpc/include/asm/kvm_ppc.h > +++ b/arch/powerpc/include/asm/kvm_ppc.h > @@ -47,6 +47,11 @@ enum emulation_result { > EMULATE_EXIT_USER, /* emulation requires exit to user-space */ > }; > > +enum instruction_type { > + INST_GENERIC, > + INST_SC, /* system call */ > +}; > + > extern int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu); > extern int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu); > extern void kvmppc_handler_highmem(void); > @@ -62,6 +67,9 @@ extern int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu, > u64 val, unsigned int bytes, > int is_default_endian); > > +extern int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, > + enum instruction_type type, u32 *inst); > + > extern int kvmppc_emulate_instruction(struct kvm_run *run, > struct kvm_vcpu *vcpu); > extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu); > @@ -234,6 +242,22 @@ struct kvmppc_ops { > extern struct kvmppc_ops *kvmppc_hv_ops; > extern struct kvmppc_ops *kvmppc_pr_ops; > > +static inline int kvmppc_get_last_inst(struct kvm_vcpu *vcpu, > + enum instruction_type type, u32 *inst) > +{ > + int ret = EMULATE_DONE; > + > + /* Load the instruction manually if it failed to do so in the > + * exit path */ > + if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) > + ret = kvmppc_load_last_inst(vcpu, type, &vcpu->arch.last_inst); > + > + *inst = kvmppc_need_byteswap(vcpu) ? swab32(vcpu->arch.last_inst) : > + vcpu->arch.last_inst; We swap needlessly when the translation failed, but I don't think it really hurts. > + > + return ret; So here we just return the return value of kvmppc_load_last_inst() ... > +} > + > static inline bool is_kvmppc_hv_enabled(struct kvm *kvm) > { > return kvm->arch.kvm_ops == kvmppc_hv_ops; > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c > index bd75902..c17f101 100644 > --- a/arch/powerpc/kvm/book3s.c > +++ b/arch/powerpc/kvm/book3s.c > @@ -467,6 +467,17 @@ mmio: > } > EXPORT_SYMBOL_GPL(kvmppc_ld); > > +int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type, > + u32 *inst) > +{ > + ulong pc = kvmppc_get_pc(vcpu); > + > + if (type == INST_SC) > + pc -= 4; > + return kvmppc_ld(vcpu, &pc, sizeof(u32), &vcpu->arch.last_inst, false); ... which simply returns the return value of kvmppc_ld(). However, kvmppc_ld() returns -ENOENT when it doesn't find a translation. We need to convert the return value space of kvmppc_ld() into an EMULATE_ name space that makes sense for this function. How about something like r = kvmppc_ld(); if (r == EMULATE_DONE) return r; else return EMULATE_AGAIN; That way we make sure that we tell the caller only "yes, all is good" or "please go back into the guest". > +} > +EXPORT_SYMBOL_GPL(kvmppc_load_last_inst); > + > int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) > { > return 0; > diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c > index 8056107..2c2b7ad 100644 > --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c > +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c > @@ -530,21 +530,14 @@ static int instruction_is_store(unsigned int instr) > static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, > unsigned long gpa, gva_t ea, int is_store) > { > - int ret; > u32 last_inst; > - unsigned long srr0 = kvmppc_get_pc(vcpu); > > - /* We try to load the last instruction. We don't let > - * emulate_instruction do it as it doesn't check what > - * kvmppc_ld returns. > + /* > * If we fail, we just return to the guest and try executing it again. > */ > - if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { > - ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); > - if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) > - return RESUME_GUEST; > - vcpu->arch.last_inst = last_inst; > - } > + if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != > + EMULATE_DONE) > + return RESUME_GUEST; This looks great. > > /* > * WARNING: We do not know for sure whether the instruction we just > @@ -558,7 +551,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, > * we just return and retry the instruction. > */ > > - if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store) > + if (instruction_is_store(last_inst) != !!is_store) > return RESUME_GUEST; > > /* > diff --git a/arch/powerpc/kvm/book3s_paired_singles.c b/arch/powerpc/kvm/book3s_paired_singles.c > index 6c8011f..bfb8035 100644 > --- a/arch/powerpc/kvm/book3s_paired_singles.c > +++ b/arch/powerpc/kvm/book3s_paired_singles.c > @@ -639,26 +639,36 @@ static int kvmppc_ps_one_in(struct kvm_vcpu *vcpu, bool rc, > > int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu) > { > - u32 inst = kvmppc_get_last_inst(vcpu); > + u32 inst; > enum emulation_result emulated = EMULATE_DONE; > + int ax_rd, ax_ra, ax_rb, ax_rc; > + short full_d; > + u64 *fpr_d, *fpr_a, *fpr_b, *fpr_c; > > - int ax_rd = inst_get_field(inst, 6, 10); > - int ax_ra = inst_get_field(inst, 11, 15); > - int ax_rb = inst_get_field(inst, 16, 20); > - int ax_rc = inst_get_field(inst, 21, 25); > - short full_d = inst_get_field(inst, 16, 31); > - > - u64 *fpr_d = &VCPU_FPR(vcpu, ax_rd); > - u64 *fpr_a = &VCPU_FPR(vcpu, ax_ra); > - u64 *fpr_b = &VCPU_FPR(vcpu, ax_rb); > - u64 *fpr_c = &VCPU_FPR(vcpu, ax_rc); > - > - bool rcomp = (inst & 1) ? true : false; > - u32 cr = kvmppc_get_cr(vcpu); > + bool rcomp; > + u32 cr; > #ifdef DEBUG > int i; > #endif > > + emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst); > + if (emulated != EMULATE_DONE) > + return emulated; Here we're already leaking the "emulated" return value into the caller. The caller in this chain should know what EMULATE_AGAIN means, so with the change above we're safe. > + > + ax_rd = inst_get_field(inst, 6, 10); > + ax_ra = inst_get_field(inst, 11, 15); > + ax_rb = inst_get_field(inst, 16, 20); > + ax_rc = inst_get_field(inst, 21, 25); > + full_d = inst_get_field(inst, 16, 31); > + > + fpr_d = &VCPU_FPR(vcpu, ax_rd); > + fpr_a = &VCPU_FPR(vcpu, ax_ra); > + fpr_b = &VCPU_FPR(vcpu, ax_rb); > + fpr_c = &VCPU_FPR(vcpu, ax_rc); > + > + rcomp = (inst & 1) ? true : false; > + cr = kvmppc_get_cr(vcpu); > + > if (!kvmppc_inst_is_paired_single(vcpu, inst)) > return EMULATE_FAIL; > > diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c > index d247d88..7bbaeec 100644 > --- a/arch/powerpc/kvm/book3s_pr.c > +++ b/arch/powerpc/kvm/book3s_pr.c > @@ -970,15 +970,24 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, > { > enum emulation_result er; > ulong flags; > + u32 last_inst; > + int emul; > > program_interrupt: > flags = vcpu->arch.shadow_srr1 & 0x1f0000ull; > > + emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); > + if (emul != EMULATE_DONE) { > + r = RESUME_GUEST; Yes, this looks good. > + break; > + } > + > if (kvmppc_get_msr(vcpu) & MSR_PR) { > #ifdef EXIT_DEBUG > - printk(KERN_INFO "Userspace triggered 0x700 exception at 0x%lx (0x%x)\n", kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu)); > + pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n", > + kvmppc_get_pc(vcpu), last_inst); > #endif > - if ((kvmppc_get_last_inst(vcpu) & 0xff0007ff) != > + if ((last_inst & 0xff0007ff) != > (INS_DCBZ & 0xfffffff7)) { > kvmppc_core_queue_program(vcpu, flags); > r = RESUME_GUEST; > @@ -997,7 +1006,7 @@ program_interrupt: > break; > case EMULATE_FAIL: > printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n", > - __func__, kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu)); > + __func__, kvmppc_get_pc(vcpu), last_inst); > kvmppc_core_queue_program(vcpu, flags); > r = RESUME_GUEST; > break; > @@ -1014,8 +1023,25 @@ program_interrupt: > break; > } > case BOOK3S_INTERRUPT_SYSCALL: > + { > + u32 last_sc; > + int emul; > + > + /* Get last sc for papr */ > + if (vcpu->arch.papr_enabled) { > + /* > + * The sc instuction sets SRR0 to point to the next inst > + */ > + emul = kvmppc_get_last_inst(vcpu, INST_SC, &last_sc); > + if (emul != EMULATE_DONE) { > + kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) - 4); > + r = RESUME_GUEST; This also looks good :). > + break; > + } > + } > + > if (vcpu->arch.papr_enabled && > - (kvmppc_get_last_sc(vcpu) == 0x44000022) && > + (last_sc == 0x44000022) && > !(kvmppc_get_msr(vcpu) & MSR_PR)) { > /* SC 1 papr hypercalls */ > ulong cmd = kvmppc_get_gpr(vcpu, 3); > @@ -1060,13 +1086,13 @@ program_interrupt: > r = RESUME_GUEST; > } > break; > + } > case BOOK3S_INTERRUPT_FP_UNAVAIL: > case BOOK3S_INTERRUPT_ALTIVEC: > case BOOK3S_INTERRUPT_VSX: > { > int ext_msr = 0; > int emul; > - ulong pc; > u32 last_inst; > > if (!(vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE)) { > @@ -1090,9 +1116,7 @@ program_interrupt: > break; > } > > - pc = kvmppc_get_pc(vcpu); > - last_inst = kvmppc_get_last_inst(vcpu); > - emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false); > + emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); > if (emul == EMULATE_DONE) { > /* we need to emulate this instruction */ > goto program_interrupt; > @@ -1105,9 +1129,8 @@ program_interrupt: > } > case BOOK3S_INTERRUPT_ALIGNMENT: > { > - ulong pc = kvmppc_get_pc(vcpu); > - u32 last_inst = kvmppc_get_last_inst(vcpu); > - int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false); > + u32 last_inst; > + int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); > > if (emul == EMULATE_DONE) { > u32 dsisr; > diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c > index ab62109..34a42b9 100644 > --- a/arch/powerpc/kvm/booke.c > +++ b/arch/powerpc/kvm/booke.c > @@ -752,6 +752,9 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) > * they were actually modified by emulation. */ > return RESUME_GUEST_NV; > > + case EMULATE_AGAIN: > + return RESUME_GUEST; Yup :). > + > case EMULATE_DO_DCR: > run->exit_reason = KVM_EXIT_DCR; > return RESUME_HOST; > diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c > index dd2cc03..4b4e8d6 100644 > --- a/arch/powerpc/kvm/e500_mmu_host.c > +++ b/arch/powerpc/kvm/e500_mmu_host.c > @@ -606,6 +606,12 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr, > } > } > > +int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type, > + u32 *instr) > +{ > + return EMULATE_FAIL; This should be EMULATE_AGAIN, no? > +} > + > /************* MMU Notifiers *************/ > > int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) > diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c > index da86d9b..c5c64b6 100644 > --- a/arch/powerpc/kvm/emulate.c > +++ b/arch/powerpc/kvm/emulate.c > @@ -224,19 +224,25 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt) > * from opcode tables in the future. */ > int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) > { > - u32 inst = kvmppc_get_last_inst(vcpu); > - int ra = get_ra(inst); > - int rs = get_rs(inst); > - int rt = get_rt(inst); > - int sprn = get_sprn(inst); > - enum emulation_result emulated = EMULATE_DONE; > + u32 inst; > + int ra, rs, rt, sprn; > + enum emulation_result emulated; > int advance = 1; > > /* this default type might be overwritten by subcategories */ > kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS); > > + emulated = kvmppc_get_last_inst(vcpu, false, &inst); > + if (emulated != EMULATE_DONE) > + return emulated; and here we're leaking again ;). It's perfectly fine to do so, but let's make sure we don't leak -ENOENT :). So here too the fix above should make things work. Alex > + > pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst)); > > + ra = get_ra(inst); > + rs = get_rs(inst); > + rt = get_rt(inst); > + sprn = get_sprn(inst); > + > switch (get_op(inst)) { > case OP_TRAP: > #ifdef CONFIG_PPC_BOOK3S > diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c > index 7efc2b7..da54e4b 100644 > --- a/arch/powerpc/kvm/powerpc.c > +++ b/arch/powerpc/kvm/powerpc.c > @@ -261,6 +261,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu) > * actually modified. */ > r = RESUME_GUEST_NV; > break; > + case EMULATE_AGAIN: > + r = RESUME_GUEST; > + break; > case EMULATE_DO_MMIO: > run->exit_reason = KVM_EXIT_MMIO; > /* We must reload nonvolatiles because "update" load/store > @@ -270,11 +273,15 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu) > r = RESUME_HOST_NV; > break; > case EMULATE_FAIL: > + { > + u32 last_inst; > + > + kvmppc_get_last_inst(vcpu, false, &last_inst); > /* XXX Deliver Program interrupt to guest. */ > - printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__, > - kvmppc_get_last_inst(vcpu)); > + pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst); > r = RESUME_HOST; > break; > + } > default: > WARN_ON(1); > r = RESUME_GUEST; -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index ceb70aa..1300cd9 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -276,32 +276,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu) return (kvmppc_get_msr(vcpu) & MSR_LE) != (MSR_KERNEL & MSR_LE); } -static inline u32 kvmppc_get_last_inst_internal(struct kvm_vcpu *vcpu, ulong pc) -{ - /* Load the instruction manually if it failed to do so in the - * exit path */ - if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) - kvmppc_ld(vcpu, &pc, sizeof(u32), &vcpu->arch.last_inst, false); - - return kvmppc_need_byteswap(vcpu) ? swab32(vcpu->arch.last_inst) : - vcpu->arch.last_inst; -} - -static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu) -{ - return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu)); -} - -/* - * Like kvmppc_get_last_inst(), but for fetching a sc instruction. - * Because the sc instruction sets SRR0 to point to the following - * instruction, we have to fetch from pc - 4. - */ -static inline u32 kvmppc_get_last_sc(struct kvm_vcpu *vcpu) -{ - return kvmppc_get_last_inst_internal(vcpu, kvmppc_get_pc(vcpu) - 4); -} - static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu) { return vcpu->arch.fault_dar; diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h index c7aed61..cbb1990 100644 --- a/arch/powerpc/include/asm/kvm_booke.h +++ b/arch/powerpc/include/asm/kvm_booke.h @@ -69,11 +69,6 @@ static inline bool kvmppc_need_byteswap(struct kvm_vcpu *vcpu) return false; } -static inline u32 kvmppc_get_last_inst(struct kvm_vcpu *vcpu) -{ - return vcpu->arch.last_inst; -} - static inline void kvmppc_set_ctr(struct kvm_vcpu *vcpu, ulong val) { vcpu->arch.ctr = val; diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index e2fd5a1..ec326c8 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -47,6 +47,11 @@ enum emulation_result { EMULATE_EXIT_USER, /* emulation requires exit to user-space */ }; +enum instruction_type { + INST_GENERIC, + INST_SC, /* system call */ +}; + extern int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu); extern int __kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu); extern void kvmppc_handler_highmem(void); @@ -62,6 +67,9 @@ extern int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu, u64 val, unsigned int bytes, int is_default_endian); +extern int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, + enum instruction_type type, u32 *inst); + extern int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu); extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu); @@ -234,6 +242,22 @@ struct kvmppc_ops { extern struct kvmppc_ops *kvmppc_hv_ops; extern struct kvmppc_ops *kvmppc_pr_ops; +static inline int kvmppc_get_last_inst(struct kvm_vcpu *vcpu, + enum instruction_type type, u32 *inst) +{ + int ret = EMULATE_DONE; + + /* Load the instruction manually if it failed to do so in the + * exit path */ + if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) + ret = kvmppc_load_last_inst(vcpu, type, &vcpu->arch.last_inst); + + *inst = kvmppc_need_byteswap(vcpu) ? swab32(vcpu->arch.last_inst) : + vcpu->arch.last_inst; + + return ret; +} + static inline bool is_kvmppc_hv_enabled(struct kvm *kvm) { return kvm->arch.kvm_ops == kvmppc_hv_ops; diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index bd75902..c17f101 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -467,6 +467,17 @@ mmio: } EXPORT_SYMBOL_GPL(kvmppc_ld); +int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type, + u32 *inst) +{ + ulong pc = kvmppc_get_pc(vcpu); + + if (type == INST_SC) + pc -= 4; + return kvmppc_ld(vcpu, &pc, sizeof(u32), &vcpu->arch.last_inst, false); +} +EXPORT_SYMBOL_GPL(kvmppc_load_last_inst); + int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) { return 0; diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 8056107..2c2b7ad 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -530,21 +530,14 @@ static int instruction_is_store(unsigned int instr) static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned long gpa, gva_t ea, int is_store) { - int ret; u32 last_inst; - unsigned long srr0 = kvmppc_get_pc(vcpu); - /* We try to load the last instruction. We don't let - * emulate_instruction do it as it doesn't check what - * kvmppc_ld returns. + /* * If we fail, we just return to the guest and try executing it again. */ - if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { - ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); - if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) - return RESUME_GUEST; - vcpu->arch.last_inst = last_inst; - } + if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != + EMULATE_DONE) + return RESUME_GUEST; /* * WARNING: We do not know for sure whether the instruction we just @@ -558,7 +551,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, * we just return and retry the instruction. */ - if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store) + if (instruction_is_store(last_inst) != !!is_store) return RESUME_GUEST; /* diff --git a/arch/powerpc/kvm/book3s_paired_singles.c b/arch/powerpc/kvm/book3s_paired_singles.c index 6c8011f..bfb8035 100644 --- a/arch/powerpc/kvm/book3s_paired_singles.c +++ b/arch/powerpc/kvm/book3s_paired_singles.c @@ -639,26 +639,36 @@ static int kvmppc_ps_one_in(struct kvm_vcpu *vcpu, bool rc, int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu) { - u32 inst = kvmppc_get_last_inst(vcpu); + u32 inst; enum emulation_result emulated = EMULATE_DONE; + int ax_rd, ax_ra, ax_rb, ax_rc; + short full_d; + u64 *fpr_d, *fpr_a, *fpr_b, *fpr_c; - int ax_rd = inst_get_field(inst, 6, 10); - int ax_ra = inst_get_field(inst, 11, 15); - int ax_rb = inst_get_field(inst, 16, 20); - int ax_rc = inst_get_field(inst, 21, 25); - short full_d = inst_get_field(inst, 16, 31); - - u64 *fpr_d = &VCPU_FPR(vcpu, ax_rd); - u64 *fpr_a = &VCPU_FPR(vcpu, ax_ra); - u64 *fpr_b = &VCPU_FPR(vcpu, ax_rb); - u64 *fpr_c = &VCPU_FPR(vcpu, ax_rc); - - bool rcomp = (inst & 1) ? true : false; - u32 cr = kvmppc_get_cr(vcpu); + bool rcomp; + u32 cr; #ifdef DEBUG int i; #endif + emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst); + if (emulated != EMULATE_DONE) + return emulated; + + ax_rd = inst_get_field(inst, 6, 10); + ax_ra = inst_get_field(inst, 11, 15); + ax_rb = inst_get_field(inst, 16, 20); + ax_rc = inst_get_field(inst, 21, 25); + full_d = inst_get_field(inst, 16, 31); + + fpr_d = &VCPU_FPR(vcpu, ax_rd); + fpr_a = &VCPU_FPR(vcpu, ax_ra); + fpr_b = &VCPU_FPR(vcpu, ax_rb); + fpr_c = &VCPU_FPR(vcpu, ax_rc); + + rcomp = (inst & 1) ? true : false; + cr = kvmppc_get_cr(vcpu); + if (!kvmppc_inst_is_paired_single(vcpu, inst)) return EMULATE_FAIL; diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index d247d88..7bbaeec 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -970,15 +970,24 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, { enum emulation_result er; ulong flags; + u32 last_inst; + int emul; program_interrupt: flags = vcpu->arch.shadow_srr1 & 0x1f0000ull; + emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); + if (emul != EMULATE_DONE) { + r = RESUME_GUEST; + break; + } + if (kvmppc_get_msr(vcpu) & MSR_PR) { #ifdef EXIT_DEBUG - printk(KERN_INFO "Userspace triggered 0x700 exception at 0x%lx (0x%x)\n", kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu)); + pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n", + kvmppc_get_pc(vcpu), last_inst); #endif - if ((kvmppc_get_last_inst(vcpu) & 0xff0007ff) != + if ((last_inst & 0xff0007ff) != (INS_DCBZ & 0xfffffff7)) { kvmppc_core_queue_program(vcpu, flags); r = RESUME_GUEST; @@ -997,7 +1006,7 @@ program_interrupt: break; case EMULATE_FAIL: printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n", - __func__, kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu)); + __func__, kvmppc_get_pc(vcpu), last_inst); kvmppc_core_queue_program(vcpu, flags); r = RESUME_GUEST; break; @@ -1014,8 +1023,25 @@ program_interrupt: break; } case BOOK3S_INTERRUPT_SYSCALL: + { + u32 last_sc; + int emul; + + /* Get last sc for papr */ + if (vcpu->arch.papr_enabled) { + /* + * The sc instuction sets SRR0 to point to the next inst + */ + emul = kvmppc_get_last_inst(vcpu, INST_SC, &last_sc); + if (emul != EMULATE_DONE) { + kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) - 4); + r = RESUME_GUEST; + break; + } + } + if (vcpu->arch.papr_enabled && - (kvmppc_get_last_sc(vcpu) == 0x44000022) && + (last_sc == 0x44000022) && !(kvmppc_get_msr(vcpu) & MSR_PR)) { /* SC 1 papr hypercalls */ ulong cmd = kvmppc_get_gpr(vcpu, 3); @@ -1060,13 +1086,13 @@ program_interrupt: r = RESUME_GUEST; } break; + } case BOOK3S_INTERRUPT_FP_UNAVAIL: case BOOK3S_INTERRUPT_ALTIVEC: case BOOK3S_INTERRUPT_VSX: { int ext_msr = 0; int emul; - ulong pc; u32 last_inst; if (!(vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE)) { @@ -1090,9 +1116,7 @@ program_interrupt: break; } - pc = kvmppc_get_pc(vcpu); - last_inst = kvmppc_get_last_inst(vcpu); - emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false); + emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); if (emul == EMULATE_DONE) { /* we need to emulate this instruction */ goto program_interrupt; @@ -1105,9 +1129,8 @@ program_interrupt: } case BOOK3S_INTERRUPT_ALIGNMENT: { - ulong pc = kvmppc_get_pc(vcpu); - u32 last_inst = kvmppc_get_last_inst(vcpu); - int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false); + u32 last_inst; + int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); if (emul == EMULATE_DONE) { u32 dsisr; diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ab62109..34a42b9 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -752,6 +752,9 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) * they were actually modified by emulation. */ return RESUME_GUEST_NV; + case EMULATE_AGAIN: + return RESUME_GUEST; + case EMULATE_DO_DCR: run->exit_reason = KVM_EXIT_DCR; return RESUME_HOST; diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c index dd2cc03..4b4e8d6 100644 --- a/arch/powerpc/kvm/e500_mmu_host.c +++ b/arch/powerpc/kvm/e500_mmu_host.c @@ -606,6 +606,12 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 eaddr, gpa_t gpaddr, } } +int kvmppc_load_last_inst(struct kvm_vcpu *vcpu, enum instruction_type type, + u32 *instr) +{ + return EMULATE_FAIL; +} + /************* MMU Notifiers *************/ int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index da86d9b..c5c64b6 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -224,19 +224,25 @@ static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt) * from opcode tables in the future. */ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) { - u32 inst = kvmppc_get_last_inst(vcpu); - int ra = get_ra(inst); - int rs = get_rs(inst); - int rt = get_rt(inst); - int sprn = get_sprn(inst); - enum emulation_result emulated = EMULATE_DONE; + u32 inst; + int ra, rs, rt, sprn; + enum emulation_result emulated; int advance = 1; /* this default type might be overwritten by subcategories */ kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS); + emulated = kvmppc_get_last_inst(vcpu, false, &inst); + if (emulated != EMULATE_DONE) + return emulated; + pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst)); + ra = get_ra(inst); + rs = get_rs(inst); + rt = get_rt(inst); + sprn = get_sprn(inst); + switch (get_op(inst)) { case OP_TRAP: #ifdef CONFIG_PPC_BOOK3S diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 7efc2b7..da54e4b 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -261,6 +261,9 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu) * actually modified. */ r = RESUME_GUEST_NV; break; + case EMULATE_AGAIN: + r = RESUME_GUEST; + break; case EMULATE_DO_MMIO: run->exit_reason = KVM_EXIT_MMIO; /* We must reload nonvolatiles because "update" load/store @@ -270,11 +273,15 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu) r = RESUME_HOST_NV; break; case EMULATE_FAIL: + { + u32 last_inst; + + kvmppc_get_last_inst(vcpu, false, &last_inst); /* XXX Deliver Program interrupt to guest. */ - printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__, - kvmppc_get_last_inst(vcpu)); + pr_emerg("%s: emulation failed (%08x)\n", __func__, last_inst); r = RESUME_HOST; break; + } default: WARN_ON(1); r = RESUME_GUEST;
On book3e, guest last instruction is read on the exit path using load external pid (lwepx) dedicated instruction. This load operation may fail due to TLB eviction and execute-but-not-read entries. This patch lay down the path for an alternative solution to read the guest last instruction, by allowing kvmppc_get_lat_inst() function to fail. Architecture specific implmentations of kvmppc_load_last_inst() may read last guest instruction and instruct the emulation layer to re-execute the guest in case of failure. Make kvmppc_get_last_inst() definition common between architectures. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> --- v4: - these changes compile on book3s, please validate the functionality and do the necessary adaptations! - common declaration and enum for kvmppc_load_last_inst() - remove kvmppc_read_inst() in a preceding patch v3: - rework patch description - add common definition for kvmppc_get_last_inst() - check return values in book3s code v2: - integrated kvmppc_get_last_inst() in book3s code and checked build - addressed cosmetic feedback arch/powerpc/include/asm/kvm_book3s.h | 26 ------------------ arch/powerpc/include/asm/kvm_booke.h | 5 ---- arch/powerpc/include/asm/kvm_ppc.h | 24 +++++++++++++++++ arch/powerpc/kvm/book3s.c | 11 ++++++++ arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 ++++-------- arch/powerpc/kvm/book3s_paired_singles.c | 38 +++++++++++++++++---------- arch/powerpc/kvm/book3s_pr.c | 45 ++++++++++++++++++++++++-------- arch/powerpc/kvm/booke.c | 3 +++ arch/powerpc/kvm/e500_mmu_host.c | 6 +++++ arch/powerpc/kvm/emulate.c | 18 ++++++++----- arch/powerpc/kvm/powerpc.c | 11 ++++++-- 11 files changed, 128 insertions(+), 76 deletions(-)